Regulating transformer



July 29, 1930. w PETERSEN 1,771,816

REGULATING TRANSFORMER Filed Oct. 2, 192a Fig.6.

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Patented July 29, 1930 PATENT OFFICE wALnnm PETERSEN, or namas'ranr,GERMANY BEGULATING TRANSFORMER Application flled.0ctober 2, 1926, SerialNo. 139,126, and in Germany September 23, 1925.

' effected under voltage or load.

The subject-matter of the present invention avoids this disadvantage byenabling the variation of the transformation ratio of a transformer tobe effected in such a manner that by the provision of at least twoparallel magnetic circuits within one and the same primary winding andof regulating windings suitably distributed and coupled to control theflux distribution to the said magnetic, circuits as desired so thatvariable voltages are induced in the secondary windings. The regulatingoperation is thus transferred from the primary or secondary windings tothe particular regulating windings provided therefor, this arrangementhaving the great advantage that only low voltages or small currentsrequire to be controlled, as the number of turns of the regulatingwindings and therefore the voltages induced therein may be chosenindependently of those of either the primary or sec-' ondary windings. 1v

The invention is illustrated in the .ac'companying diagrammatic drawingswhich {5 show, by way of example, a number of difterent arrangementsembodying-the invention.

Figure 1 shows one leg portion of a single or polyphase transformer incross section;

Figure 2 is a sideelevationthereof;

Figures3, land 5 show also by side elevation one leg portion of threedifferent trans former constructions; v Figure 6 gives a diagrammaticreproduction of a transformer with a controlling de- 4 vice for theregulating windings.

the number of turns 8 o Inthe transformer construction shown in Figure1, which represents only one leg portion of'the transformer, the core'of the represented leg portion of the transformer is subdivided into twocore sections a, and a The primary winding, which surrounds both coresections, is indicated at 0, while the spools of the secondary windingare indicated lat d d andthe regulating windings at f v t The two halvesof the secondary winding oZ and 03 are oppositely connected, and the tworegulating windings f and f ,can be coupled in normal series connectionor so connected in series that the corresponding electromotive forcesare of respectively opposite directions, as indicated in the draw- Tor aconstant voltage impressed on the primary winding 0 the total flux Ntraversing the core-sections is constant. This flux divides into twoflux portions N and N traversing the core sections a and a respectivelyin the inverse ratio of the number of turns S 1 and 8 ofthe regulatingwindings f and f The voltage induced by theitotal flux N in t hesecondary winding (1 of the core a will be denoted by E =kNs ==-constant(4) similarly the voltage induced by'the flux portion N in'thesecondary. winding d having a nugnben of turns 8 will be denotedby and,similarly, the voltage induced by the flux portion, N -in the secondarywinding d having a number of turns 8 will be denoted by zz z n Byreference to Equations 2 and 3, I obwith opposing connection of J and dit will be apparent that the secondary voltage In the case in which thenumbers of turns of the two secondary winding sections are equal to oneanother, that is to say 21 22 Equation 7 will take the following formThe large range of regulation expressed by Equation 7 may be furtherincreased, if the two regulating windings, instead of being directlycoupled together are coupled through an ordinary transformer, or anauto-transformer having a variable transformation ratio." Thistransformation ratio may be defined by the equation.

E82: ai.

in which E is the voltage of the side of the intermediate transformerconnected to f and E is the voltage of the side of the intermediatetransformer connected to f The factor a can have a positive or negativevalue, as desired.

- A further constructional example is shown in Figure 2. In this figurethe secondary winding section al is omitted; as regards the remainingelements the core sections (1 and a the primary winding 0 and theregulating windings f and f are the same as in Figure 1, Z) I) being theyoke of a single or polyphase transformer.

The operation of regulation is the same as before, the total flux Nremaining constant and being distributed by means of the regulatingwindings in any desired ratio between the two core sections a and aEquation 8 of the simplified switching corresponds to s E 31 E 31+ 32(9) In the further constructional examples shown in Figures 3 and 4, thecore is constructed as before, with at least two core sections, a and ain Figure 3, a a a in Figure 4, which are connected by means of magneticbrid es h h etc. In the simple example s own in Figure 3 the coresection a only carries the coils d d d etc. of the secondary winding.The regulating windings are indicated at f and f 9 and g and Z and Z Theprimary winding is indicated at 0 and the yoke at b.

In this construction the flux, which has an inducing action on thesecondary winding can be varied in each (3011 section qtnte 1nde--pendentlyof the other coil sections. If, for example, f (9 Z isshort-circuited, and f (9 Z is open-circuited, the effective flux willexclusively traverse the core section (1 By a parallel connection of fand f and by varying the number of turns of f and f and flux can, as inthe case of Figures 1 and 2, be transferred to the upper part of thecore section a By short-circuiting f and opencircuiting f the totaleffective flux will traverse the winding d (Figure 3) and will passthrough the bridge [L as indicated in Figure 3. In a manner readilyunderstood the flux traversing the windings (Z and d can be transferredor deviated in any desired stages from al to a In the furtherconstructional example of Figure 5, b, b are the yokes of a single orpolyphase transformer, a (1 the core sections of the transformer leg, ha connecting bridge between the two core sections, 0 the primary windingof the leg, (Z a secondary winding located on the connecting bridge 72.,and e, f, i and Z0 are the regulating windings.

In the low voltage condition of the secondary winding (1 the regulatingwindings e and f as also the winding 1' and is having equal numbers ofturns, are connected in parallel with one another. The effective fluxtraverses the core sections a and a the bridge it being not traversed byfiuX. If it is desired that cl should be inductively influenced to thefull extent by the effective flux, e and is must be short-circuited, andf and 6 connected in parallel with one another. The flux takes the paththrough across it and through i. If, on the other hand, f and i areshort-circuited and e and 7c are connected in parallel with one another,the flux will pass through it in the opposite direction to t at givenabove.

The substantially continuous or graduated adjustment of the voltage onthe winding d will evidently take place as in the constructionalexamples of Figures 1 or 2. The regulating windings e and is on the onehand, and f and i on the other hand, have corresponding characteristics,so that, forthis reason, a and k on the one hand, and f and i on theother hand, can be connected in circuit to one winding corresponding tof and f in Figures 1 and 2. In the utilization of the inventive idea ina reactance coil, which is a light- 1y loaded transformer without aSBCOlldfll; winding, the secondary windings (Z and 2 are dispensed with,for instance, in the constructional form of Figures 1 and 2.

The core sections a,, a, can be constructed so as to have diiferentmagnetic reluctances.

If, for instance, (1 has a low magnetic reluctance, whilst a has a highmagnetic reluctance, the primary winding will constitute a smallreactance when the regulating winding has deviated the flux to (1. When,on the contrary, the flux is deviated to a, by the regulating winding,the primary winding will increase-in reacta'nce.

In order to show how the regulating windings may be controlled, acontrol device is represented in Figure 6 .for re ating the connectionsof these windin s. n this figure the movable element M' w ich as shownis divided into three conducting sections separated by insulated partsmay be moved over a series of contacts to change the connections of theregulating windings. This figure shows a sim 1e conventional switchingarrangement w ereby the re ulating windings may be connected in parallel or in series and also whereby either windinglf or f, may be.

open circuited while the ot er is short circuited. It is apparent thatadditional contacts and connections may be employed to change the numberof turns in either of these windings to vary the regulating efiect. Anyconvenient mechanism may be employed to move the element M over thecontacts in either direction to bring about the desired connections.

As in all transformers, the foregoing conditions are reversible, theprimary and secondary windings being interchangeable. Furthermore theimproved transformer can serve, for example, to efiect transformation.

from constant current in the windings (I and d to constant voltage inthe winding 0.

What I claim is 1. A regulatin transformer comprising a magnetic coresubdivided into a plurality of core sections, a primary winding with itsturns extending around all of said core sections, a secondary windinghaving its turns on parts thereof and independent regulating windingsinductively related to said core sections, arranged to be excited bysaid primary winding and controlling means to connect said regulatingwindings in regulable manner with respect to each other and to said coresections so as to allow a variation of the magnetic flux distributionwith respect to the secondary winding.

2. A regulating transformer comprising a magnetic core subdivided into aplurality of core sections, at least one magnetic connection bridgebetween said core sections, a rimary winding with its turns extendingaround all of said core sections, a secondary winding having its turnson parts thereof and independent regulating windings inductively relatedto said core sections, arran ed to be excited by said primary winding ancontrolling means to connect said regulating windings in regulablemanner with respect to each other and to said core sections andconnection ranged to be excited by said primary winding and controllingmeans to connect said regulating windings in regulable manner withrespect to each other and to said core sections so as to allow avariation of the magnetic flux distribution with respect to thesecondary winding.

In witness whereof I have hereunto signed my name this 17th day of Setember, 1926.

WALDEMAR P TERSEN.

